Full wave rectifier assemblies

ABSTRACT

A full wave rectifier assembly for use in an alternator includes first and second curved terminal plates. The first terminal plate carries a set of diodes with their cathodes electrically connected to the first plate, and the second terminal plate carries a second set of diodes with their anodes electrically connected to the second plate. The first and second plates are physically interconnected in insulated relationship when the assembly is mounted in an alternator, and the first and second terminal plates are so shaped that when the first and second plates are interconnected then the diodes lie substantially in the same plane.

United States Patent FULL WAVE RECTIFIER ASSEMBLIES 4 Claims, 4 DrawingFigs.

U.S. Cl 310/68 Int. Cl 11021: 11/00 Field 01' Search 310/68 R,

Primary Examiner-D. F. Duggan Attorney-Holman & Stern ABSTRACT: A fullwave rectifier assembly for use in an alternator includes first andsecond curved terminal plates. The first terminal plate carries a set ofdiodes with their cathodes electrically connected to the first plate,and the second terminal plate carries a second set of diodes with theiranodes electrically connected to the second plate. The first and secondplates are physically interconnected in insulated relationship when theassembly is mounted in an alternator, and the first and second terminalplates are so shaped that when the first and second plates areinterconnected then the diodes lie substantially in the same plane.

PATENTEDBECZHSYI 3329530 sum 3 0F 3 M 1W day miw FULL WAVE RECTIFIERASSEMBLIES This invention relates to full wave rectifier assemblies foruse in alternators.

A full wave rectifier assembly according to the invention includes afirst conductive terminal plate carrying a first set of diodes withtheir cathodes electrically connected to the first terminal plate, asecond terminal plate carrying a second set of diodes with their anodeselectrically connected to the second terminal plate, means forphysically interconnecting the first and second terminal plates ininsulated relationship, the first and second terminal plates being soshaped that when the terminal plates are physically interconnected thendiodes lie substantially in the same plane and constitute pairs ofdiodes, each pair of diodes comprising a first diode carried by thefirst terminal plate and a second diode carries by the second terminalplate, the shape of the terminal plates being such that the first andsecond diodes of each pair of diodes are adjacent one another, theassembly further including conductive connectors, associated with saidpairs of diodes respectively, each connector electricallyinterconnecting the anode of said first diode of the respective pair ofdiodes to the cathode of said second diode of the respective pair ofdiodes.

One example of the invention is illustrated in the accompanying drawingswherein:

FIG. 1 is a sectional view of an alternator,

FIG. 2 is a sectional view on the line B-B in FIG. 1,

FIG. 3 is a sectional view on the line C-C in FIG. 2, and

FIG. 4 is a sectional view of the brush assembly shown in H6. 1.

Referring to the drawings, the alternator includes a frame 11 carryingfirst and second bearing assemblies 12, 13. .lournaled for rotation inthe bearing assemblies 12, 13 is a rotor shaft 14 which carriesintermediate its ends, between the bearing assemblies 12, 13, a rotorassembly 15. The rotor assembly 15 includes a pair of pole pieces oneach side of a core carrying a rotor winding, and the rotor assembly 15is rotatable with the shaft 14, within a stator assembly 16 carries bythe frame 11. The shaft 14 projects at one end from the hearing assembly12 and is adapted to receive a fan, and a pulley through which the rotorshaft is driven. At its opposite end, the rotor shaft 14 projects fromthe bearing assembly 13, the rotor shaft 14 terminating within agenerally cylindrical portion 17 of the frame 11. The end of the rotorshaft 14 remote from the bearing assembly 12 is formed with acylindrical bore within which is received a spigot 19 integral with aslip ring unit 18. The slip ring unit 18 includes a moulded bodyincluding a plain circular face extending in a plane at right angles tothe axis of the shaft 14. Said face of the moulded body of the slip ringunit 18 includes a central conductive disc 21 which lieswithin aconductive annulus 22, the disc 21 being insulated from the annulus 22[The disc 21 is concentric with the annulus 22, and the disc 21 and theannulus 22 constitute the brush engaging surfaces of the slip ring unit.The spigot 19 of the slip ring unit 18 is of cruciform cross section,and is received as an interference fit in the bore in the rotor shaft14, so that the slip ring unit 18 rotates with the rotor shaft 14. Aspring clip (not shown) is engaged between the spigot 19 and the wall ofthe bore in the shaft 14, and aids the interference fit between thespigot 19 and the wall of the bore in the shaft.

14, in maintaining the slip ring unit 18 in engagement with the shaft14. Since the bore in the shaft 14 is cylindrical, and the spigot 19 isof cruciform cross section, then four equiangularly spaced passages aredefined between the spigot 19 and the wall of the bore shaft 14. A pairof connecting leads are provided for electrically interconnecting theannulus 22 and the disc 21 of the unit 18 to the rotor winding, andthese leads extend through the bearing assembly 13 along a diametricallyopposite pair of the passages defined between the wall of the bore inthe shaft 14 and the spigot'19. At the side of the bearing 13 adjacentthe rotor assembly 15, that is to say the side remote from the unit 18,the leads extend through respective passages 23 through which thecylindrical bore in the shaft 14 communicates with, the exterior of the.shaft.

The provision of a face-type slip ring assembly which is secured to therotor shaft by engaging a spigot integral with the slip ring assembly ina bore in the shaft enables the overall length of the alternator to bekept to a minimum.

The inner end of the portion 17 of the frame 11 is closed by the bearingassembly 13, and the outer end of the portion 17 is closed by a mouldedsynthetic resin brush box 24. The brush box 24 is engaged as aninterference fit with the frame 11, the brush box 24 including a pair ofspigots 25 which carry spring clips 26 and which are received as a pushfit in corresponding bores 27 in the frame 11 adjacent the portion 17 ofthe frame 11 (FIG. 4). The brush box 24 includes a pair of integralhollow spigots 28 which extend towards the slip ring unit 18, and whichreceive respective brushes 29. The brushes 29 include respectiveconductive carriers 31 which extend through slots in the walls of thespigots 28 and which serve to guide the brushes 29 for sliding movementin the spigots 28. The brushes are urged into engagement with theannulus 22 and the disc 21 of the slip ring unit 18 respectively, byrespective compression springs 32 which act between the carriers 31 andthe brush box 24. Each of the carriers 31 has electrically connectedthereto a conductive braid 33 which is electrically connected to arespective terminal secured to the exterior of the brush box 24. Thus,the slip ring unit and brushes of the alternator are completely enclosedby a housing defined by the bearing assembly 13, the portion 17 of theframe and the brush box 24.

The alternator is a three-phase alternator, and is provided with a fullwave rectifier. The full wave rectifier includes a pair of arcuateterminal plates 35, 36 each of which includes a pair of portionsindicated by the sufiixes a and b which are interconnected by aconductive integral neck indicated by the suffix c. The plates 35, 36are arranged with the portion 35b of the plate 35 between the portions36a, 36b of the plate 36, and the portion 36b of the plate 36 betweenthe portions 35a, 35b of the plate 35. The plate 35 carries three diodes37, 38, 39, with their anodes electrically connected to the plate 35 andin heat exchange relationship therewith. The diode 37 is carried by theportion 35a of the plate 35 while the diodes 38, 39 are carried by theportion 35b of the plate 35. Similarly, the plate 36 carries threediodes 41, 42, 43 with their cathodes electrically connected to theplates 36, and in heat exchange relationship therewith, the diode 41being carried by the portion 36a of the plate 36 while the diodes 42, 43are carried by the portion 36b of the plate 36. The portion 360 of theplate 36 includes a lug which overlaps a corresponding lug at one end ofthe portion 35b of the plate 35, at its opposite end the portion 35b ofthe plate 35 includes a lug which overlaps a corresponding lug at oneend of the portion 36b of the plate 36, and at its other end the portion36b of the plate 36 includes a lug which overlaps a corresponding lug onthe portion 35a of the plate 35. The plates 35, 36 are secured to oneanother by means of bolts 44, 45, 46 which extend through the lugs ofthe plates 35, 36 respectively. The lugs of the plates 35, 36 areinsulated from one another by insulating washers, and the bolt 45 isinsulated from both of the plates 35, 36. The bolt 45 physicallyconnects the plates 35, 36 to the frame 11 of the alternator and afurther pair of bolts 47 connected to but insulated from the plates 35,36 respectively aid the bolt 45 in securing the plates 35, 36 to theframe 11. The bolt 44 is electrically connected to the plate 35 butinsulated from the plate 36, while the bolt 46 is electrically connectedto the plate 36 but insulated from the plate 35. Thus, the bolts 44, 46constitute the positive and negative output terminals of the alternatorrespectively. Each of the diodes is supported on a part of therespective portion of the plates 35, 36 and is surrounded by passagesthrough which air flows in use to aid cooling of the diodes. The plates35, 36 are formed from relatively thick material, and so constitute heatsinks for the diodes, and are so shaped that the diodes 37, 38, 39, 41,42, 43 lie substantially in the same plane.

The full wave rectifier further includes three phase plates 49,51, 52,,each of which is stamped from copper sheet. The

phase plates 49, 51, 52 are supported by the bolts 44, 45, 46respectively and are insulated therefrom. Each of the phase platesincludes a center region which is mounted on but insulated from therespective bolts 44, 45, 46 and extending from the central region ofeach of the phase plates, in opposite directions, is a pair of integralarms. One arm of the phase plate 49 is electrically connected to thecathode of the diode 37, while the other arm of the phase plate 39 isconnected to the anode of the diode 43, onearm of the phase plate 51 iselectrically connected to the anode of the diode 42, while the other armthereof is connected to the cathode of the diode 38, and one arm of thephase plate 52 is electrically connected to the cathode of the diode 39while the other arm thereof is electrically connected to the anode ofthe diode 41. Moreover, the central region of each of the phase plates49, 51, 52 includes a terminal which receives a lead whereby the phaseplate is electrically connected to the phase winding of the stator ofthe alternator. Each of the phase plates 49, 51, 52 includes a diodesupporting region indicated by the suffix a. The regions 49a, 51a 52a ofthe phase plates carry respective field diodes 53, 54, 55 with theiranodes electrically connected to the regions 49a, 51a, 52a respectively.

The bolts 47 further serve to mount a voltage regulator 56 within theconfines of the frame 11, and the necessary electrical connectionsbetween the terminals of the brushes 29, the cathodes of the fielddiodes 53, 54, 55 and the voltage regulator 56 are made by way ofconductive leads.

it will be appreciated that since the brush box 24 is engaged as a push'fit with the frame 11, then it can be easily detached to facilitatereplacement of the brushes 29.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

l. A full wave rectifier assembly, for use in a three-phase alternator,comprising,

A first arcuate conductive terminal plate having first and secondportions spaced apart by an integral neck,

first, second and third semiconductor diodes carried by said firstterminal plate with their cathodes electrically connected to the plate,said first and second diodes being carried by said first portion andsaid third diode being carried by said second portion,

a second, arcuate conductive terminal plate having first and secondportions spaced apart by an integral neck, fourth, fifth, and sixthsemiconductor diodes carried by said second terminal plate with theiranodes electrically connected to the plate, said fourth and fifth diodesbeing carried by the first portion of the second plate and said sixthdiode being carried by the second portion of the plate,

means physically interconnecting said first and second terminal platesin insulated relationship with the first portion of the first terminalplate positioned between the first and second portions of the secondterminal plate and the first portion of the second terminal platepositioned between the first and second portions of the first terminalplate, so that the first and sixth diodes are adjacent one another, thesecond and fifth diodes are adjacent one another, and the third andfourth diodes are adjacent one another, and

first, second and third conductive connectors, said conductiveconnectors electrically interconnecting respectively the anode of thefirst diode and the cathode of the sixth diode, the anode of the seconddiode and the cathode of the fifth diode, and the anode of the thirddiode and the cathode of the fourth diode.

2. An assembly as claimed in claim 1 wherein the regions of the terminalplates around the diodes are perforated to define passages through whichcooling air can flow.

3. An assembly as claimed in (any one of the preceding claims) claim 1wherein each of said first, second and third connectors (each include)includes a region which carries a respective semiconductor diode, thediodes carried by the connectors each having a terminal electricallyconnected to the respective connector.

4. An assembly as claimed m claim 1 wherein said connectors constitutepart of the phase connections to the diodes of the rectifier.

1. A full wave rectifier assembly, for use in a three-phase alternator,comprising, A first arcuate conductive terminal plate having first andsecond portions spaced apart by an integral neck, first, second andthird semiconductor diodes carried by said first terminal plate withtheir cathodes electrically connected to the plate, said first andsecond diodes being carried by said first portion and said third diodebeing carried by said second portion, a second, arcuate conductiveterminal plate having first and second portions spaced apart by anintegral neck, fourth, fifth, and sixth semiconductor diodes carried bysaid second terminal plate with their anodes electrically connected tothe plate, said fourth and fifth diodes being carried by the firstportion of the second plate and said sixth diode being carried by thesecond portion of the plate, means physically interconnecting said firstand second terminal plates in insulated relationship with the firstportion of the first terminal plate positioned between the first andsecond portions of the second terminal plate and the first portion ofthe second terminal plate positioned between the first and secondportions of the first terminal plate, so that the first and sixth diodesare adjacent one another, the second and fifth diodes are adjacent oneanother, and the third and fourth diodes are adjacent one another, andfirst, second and third conductive connectors, said conductiveconnectors electrically interconnecting respectively the anode of thefirst diode and the cathode of the sixth diode, the anode of the seconddiode and the cathode of the fifth diode, and the anode of the thirddiode and the cathode of the fourth diode.
 2. An assembly as claimed inclaim 1 wherein the regions of the terminal plates around the diodes areperforated to define passages through which cooling air can flow.
 3. Anassembly as claimed in (any one of the preceding claims) claim 1 whereineach of said first, second and third connectors (each include) includesa region which carries a respective semiconductor diode, the diodescarried by the connectors each having a terminal electrically connectedto the respective connector.
 4. An assembly as claimed in claim 1wherein said connectors constitute part of the phase connections to thediodes of the rectifier.